Machine for automatically grinding thread gauges and the like



July 10, 1945.

w. J. BAUER 2,380,286

MACHINE FOR AUTOMATICALLY GRINDING THREAD GAUGES AND THE LIKE 5 Sheets-Sheet Filed July 10, 194? INVENTOR W/L L/A M 5/; use

4 T TORWEK July 10,1945, w. J. BAUER 2,380,286

MACHINE FOR AUTOMATICALLY GRINDING THREAD GAUGES AND THE LIKE Filed July 10, 1942 5 Sheets-Sheet 2 1 INVENTOR.

ML 1. [AM d. 3405/? AT 70mm)? w. J. BAUER MACHINE FOR AUTOMATICALLY GRINDING THREAD GAUGES AND THE LIKE July 10,- 1945,

Filed July 10 1942 5 Sheets-Sheet 3 IN VENTOR. WILL/AM (A B4 UER A T TOPNE'K July 10, 1945. w. J. Aur-m 2,380,286

MACHINE FOR AUTOMATICALLY GRINDING THREAD GAUGES AND THE LIKE Filed July 10 1942 5 Sheets-Sheet 5 INVENTOR- W/L LIAM 11 5 4115? ATTORNfX Patented July 10, 1945 MACHINE FOR AUTOMATICALLY GRINDING THREAD GAUGES AND THE LIKE William J. Bauer, New York,N. Y., assignor of fifty one-hundredths to John L. Dudley and fifty one-hundredths to James J. Moroney, both of Pleasantville, N. Y

Application July 10, 1942, Serial No. 450,427

6 Claims.

. tially as follows: Annealed but not hardened steel is first machined to the approximate final form'of the gauge and the thread out thereon. After this gauge is hardened, which invariably produces distortion; and to secure accuracy of thread form and pitch a grinding wheel is run over the thread and successively manually fed inwardly to remove the inaccuracies caused by distortion resulting from the hardening process. As the grinding wheel wears with each grinding cycle, it is necessary for an operator to watch the whole operation with great care and, when 'the grinding wheel has worn sufficiently, to remove said wheel and re-form or dress its grinding surface. The wheel must then again be reset in the machine with great care so that during the successive grindings it will track properly with the part being ground.

All of this involves not only constant attention and care on the part of an'operator, but requires also that such operator be highly skilled. The finished article, furthermore, depends upon the care' and skill and experience of the operator to a very marked degree.

The present invention has for an object to render the production of these thread and like gauges largely automatic.

A further object of the invention is to provide a novel. method' which eliminates any necessity of regrinding a thread because of distortion thereof.

Another object of the invention is to provide for the automatic dressing of the grinding wheel used for cutting the threads, as well as for the automatic cross-feeding of the grinding wheel. Still another. object of the invention resides in novel constructional features of the machine utilized for the carrying out of the novel process.

In carrying out the process, a rough machining. of annealed but not hardened steel stock is effected to provide a blank of suitable but .only approximate contour, and the blank is then hardened. Thereupon, the blank is machined to the exact final size and contour desired, and the thread is cut therein automatically by a suitable grinding wheel. The accuracy of grinding, furthermore, is maintained by periodically dressing the wheel; that is to say, during a period in which it is temporarily withdrawn from the surface of the blank, for example, at the completion of each cycle of grinding or engagement with the blank. The successive cycles of grindrespective engagement therewith, the carrier,

ing with increment of cross-feed of the grinding wheel are maintained automatically together with the dressing operation until the desired depth of thread is attained.

The nature of the invention, however, will best be understood when described in connection with the accompanying drawings, in which:

Fig. 1 is a front elevation of the novel grinding machine with a blank in position for having thread ground therein.

Fig. 2 is a plan thereof. I

Figs. 3 and 4 are elevations of the respective ends of the machine.

Fig. 5 is a fragmentary plan of the machine bed with carriage movable thereon.

Figs. 6 and '7 are transverse sectional views taken respectively on the lines 6-6 and |-l, Fig. 5, and looking in the direction of the arrows.

' Fig. 8 is a fragmentary plan view, and Fig. 9 a fragmentary elevation of the grinder wheel dressing means and feeding mechanism therefor. both views being on an enlarged scale.

Referring to the drawings, l0 designates a suitable supporting frame having the bed ll over which is adapted to travel longitudinally thereof, as well as to have a transverse movement relatively thereto, a slide-rest or carrier l2. On the bed is mounted an adjustable tailstock I3 for retaining between the same and a rotatable chuck M the blank l-5 to be ground as hereinafter set forth. Rotation of the blank is derived, for example, from a belt l6 through the stepped pulley l1 whereby the desired rotational velocity maybe imparted to the blank.

Power from the belt I6 is communicated through intermediate gearing 20 to a pair of horizontally disposed lead screws 2| and 22,. the former being-driven directly and the latter therefrom through a pair of spur gears 23, said lead screws running in opposite directions. These lead screws are rotatably mounted in the frame below the bed ll thereof and are designed to be alternatively engaged by a downward extension 24 of the carrier. To this end, the carrier extension is provided on its opposite vertical faces with nut elements 25 and 26 which are open or only .half of a complete nut. I These elements are disposed adjacently the corresponding lead screws and are adapted for with extension being laterally displaceable to this drawn laterally and engaged bythe other of the lead screws to return the carrier to its initial location, whereupon it is moved inwardly toward the blank in being laterally displaced for engage.- ment with the advancing lead screw. This lead screw provides the proper feed to conform to the desired thread to be cut, or rather ground, in

the blank.

This action is effected by a suitable grindin member mounted for continuous rotation on the carrier i2 and driven from a motor 3i also mounted upon the carrier.

As hereinbefore noted, the reciprocation 0f the carrier and the displacements thereof are to be effected automatically as through suitable stops 32 and 33 adjustably secured to the upper surface of the carrier, said stops being provided with respective up-turned lips 34 and 35 at their outer ends. These are adapted for engagement with continuously rotatable deflecting means such as the spring-urged yieldable arms 36 and 3)? mounted upon and rotatable with corresponding disks 38 and 39. These disks rotate in opposite directions, that is to say, in the direction opposite the advance of the corresponding carrier stop, the yieldable means being adapted for engagement with the lip of such stop when the latter comes within the orbit of such deflecting means, imparting thereby to the carrier a lateral displacement. Movement for effecting the rotationof the disks 38 and 39 is received through intermediate gearing, Fig. 6 of the drawings, from one of the lead screws,'preferably the driven lead screw 22.

In order to admit of this lateral'displacement of thecarrier which is mounted for reciprocation through a plate 40 movable in lateral ways 46 of a housing 42 attached to frame Ill along the front thereof, said plate is provided with a succession of longitudinally disposed .slots 43 through which pass corresponding screws 44 threaded into the extension 24 of the carrier.

Over the plate 40 is provided a longitudinally extending cover plate 45 which is provided with diagonally disposed slots 46 coaxial with the slots 43, a screw 44 passing through both of these slots and its head overlapping the latter. Thi will permit the assembly of the carrier and extension to allow of relative motion or lateral displacement between plate 40 and the extension to accommodate the movement necessary for the alternative engagement of the nut elements 26 and 26 with the respective lead screws 2| and 22.

; The grinding member 30 is mounted upon the carrier I2 for manual cross-feed or adjustment thereon in the usual manner, as in being dovetailed therewith, as well as for automatic feed of the grinding means'toward the blank I! during the successive cycles of operation. That is to say, after a out has been made, and the grinder withdrawn withits carrier from the blank, a feeding of the grinding means takes place substantially upon the completion ofthe return movement of the carrier. For example, a pawl 50 mounted upon a rigid portion of the frame In rides over the teeth of a ratchet wheel 5| so that when the carrier again advances after first havting been displaced laterally, a predetermined rotation of ratchet wheel Si is effected and imparts lateral displacement of the carrier.

drawings, there is mounted above the grinding means or wheel 30 a pair of grinding elements 65 and 56, such as diamond dressers, the same being removably mounted in corresponding holders 5'? and 56 designed to direct the grinding element at the proper angle for contact with the periphery of the grinding means. A progressive downward feed is' designed to be imparted to the holders through the rotation of lead screws 59and 66 fitting corresponding threads 6! and 62 of a block 63 carrying. the holders 5! and 58. The proper rotational movement is imparted to these lead screws through intermediate gearing and a ratchet wheel 65 designed to be intermittently rotated by an advancing pawl 66 carried by a slide '3 mounted in a block 68 for relative longitudinal movement thereof. The slide is springurged by means of a pair of springs 65! connecting the block and slide, and has extending outwardly from the block a plunger portion iii. It will be understood that all of the foregoing mechanisms are mounted upon and move with the carrier i2. The said projecting portion is designed to engage with a stop element Ii, adjustably mounted upon a fixed portion of the frame as upon a bracket I2 attached thereto, engagement between the two occurring substantially at the termination of the return movement of the carrier. When such contact occurs, the pawl 66 will be temporarily pushed ahead to rotate ratchet wheel 65 and when the carrier again advances, said pawl will slide over the teeth of the ratchet upon interruption of the contact between plunger portion I0 and the stop H, the plunger portion returning to its normal extended position, indicated in Fig. 8, under the influence of the springs 69 and thus being positioned for a subsequent feed of the dressing means now being applied to the machine, lead screw 2l,

being in engagement with the extension 24 of the carrier, will cause the latter to be longitudinally advanced along the blank until stop 33 is engaged by the deflecting member 31 which effects This results in disengagement of the extension 24 with lead screw 21 and its engagement with lead screw .22 for return movement of the carrier to its initial location. At this-point, the stop32 will be engaged by deflecting member 36 to reestablish the engagement between the extension 24 and lead screw 2| for, the advance movement of the grinding wheel 30. To this, however, there has been imparted in the meantime an increment of crossfeed through the pawl andratchet mechanism 50-6I so that actual grinding of the blank will occur. This takes place at each successive cycle so that the desired depth of the thread is thus automatically eventually attained; and it will not be necessary, furthermore,to withdraw the grinding wheel for dressing the same as this is also accomplished automatically through engagement of the plunger with the ship H whereby the dressing means are periodically fed toward the wheel by theratchet mechanism 65.

I claim:

1. In a machine for grinding metal articles: a,

supporting frame, a support for a blank carried by saidframe, means to rotate the blank in the support, a rotary grinder associated with the support adapted for movement radially toward and away'froma blank retained therein and including 'a laterally and longitudinally movable supporting carrier, means to advance the grinder with carrier longitudinally'of the blank when the grinder is in contact therewitlnmeans to return said grinder withcarrier longitudinally of the blank when withdrawn therefrom, together with means for displacing the grinder carrier laterally in opposite directions respectively at the 'completion of its advance and of its return longitu dinal movements, dressing means movable with means into contact with the grinder, and means adapted to contact the carrier during its return the carrier and associated with the grinder, to-.- gether with means for feeding said dressing movement .for actuating the means for feeding th dressing means;

2. In a machine for grinding metal articles: a supporting frame, asupport for a'blank carried by said frame, means to rotate the blank in the support, a rotary grinder associated with the sup- Port adapted for movement radially toward and away from ablank retained therein and including a laterally and longitudinally movable supporting carrier, means to advance the grinder with carrier longitudinally of the blank when the grinder is in contact therewith, means to return said grinder with carrier longitudinally of the blank when withdrawn therefrom, together with means for displacing the grinder carrier laterally in opposite directions respectively at the completion of its advance and of its return longitudinal movements, means movabl with the carrier for cross-feeding the grinder thereon toward the blank, means adapted to contact the carrier during its return movement for actuating the cross-feed means, dressing means movable with the carrier and associated with the grinder, together with means for feeding said dressing means into contact with the grinder, and means adapted to contact the carrier during its return movement for actuating the means for feeding the dressing means.

3. In a machine for grinding metal articles: a supporting frame, a support for a blank carried by said frame, means to rotate the blank in the support, a rotary grinder associated with the support adapted for movement-radially toward and away from a blank retained therein and in- Cluding a laterally and longitudinally movable supporting carrier bearing oppositely disposed open nut elements, a lead screw adapted for engagement with one of the nut elements to ad- Vance the carrier with grinder longitudinally of the blank, a second lead screw adapted for engagement with the other of the nut elements to return said carrier with grinder, and means adapted to contact the carrier at the ends of its reciprocations to displace the carrier laterally for engagement of its respective nut elements with a corresponding lead screw.

I 4. In a machine for grinding metal articles: a supporting frame, a support for a blank carried by said frame, means to rotate the blank in the support, a rotary grinder associated with the support adapted for movement radially toward and away from a blank retained therein and including a laterally and longitudinally movable supporting carrier bearing oppositely disposed open nut elements, a lead screw adapted for engagement with one of the nut elements to advance the carrier with grinder longitudinally of the blank, a second lead screw adapted for engagement with the other of the nutelements to return said car.-'

rier with grinder, and means adapted to contact the carrier atthe ends of its reciprocations to displace the carrier laterally for engagement of its respective nut elements with a corresponding 5. In a machine for grinding metal articles: a supporting frame, a support for a blank carried by said frame, means to rotate the blank in the port adapted for movement radially toward and support, a rotary grinder associated with the support adapted for movement radially toward and away from ablank retained therein and including a laterally and longitudinally movable sup porting carrier bearing oppositely disposed open nut-elements, a' pair of lead screws and means to rotate the same continuously, and means actuated from the movement of one of the screws to displace laterally the carrier into engagement with.

the other of the screws.

6. In a machine for grinding metal articles: a supporting frame, a support for a blank carried by said frame, meansv to rotate the blankjn the support, a rotary grinder associated with the supaway from a blank retained therein and including a laterally and longitudinally movable supporting carrier bearing oppositely disposed open Vnut elements, a pair of lead screws and means to rotate the same continuously, and a pair of-fixedly located deflecting means rotated by one of the lead screws and each including a yieldable defleeting element, together with means movable with the carrier for engagement-with the respective deflecting elements at opposite ends of its travel whereby to displace the carrier laterally.

WILLIAM J. BAUER. 

